+### Semantics of the Attributes
+
+#### service attribute
+
+Translates to DNS `SRV` RR, only it is located in the subdomain tree
+two levels higher than the `SRV` record would. For example, a
+`"service"` attribute in the `"map"` hieararchy at the point
+corresponding to the FQDN "sub.dom.bit" with the value
+
+```
+"service": [ ["imap", "tcp", 0, 0, 143, "mail.host.com" ],
+ ["smtp", "tcp", 0, 0, 25, "relay.host.com"] ]
+```
+
+corresponds to two `SRV` RRs at two different points in the
+subdomain tree:
+
+```
+_imap._tcp.sub.dom.bit. IN SRV 0 0 143 mail.host.com.
+_smtp._tcp.sub.dom.bit. IN SRV 0 0 25 relay.host.com.
+```
+
+In addition to these, an `MX` RR is syntesized at the "sub.dom.bit"
+level:
+
+```
+sub.dom.bit. IN MX 0 relay.host.com.
+```
+
+Note: Hostname element **must** be specified as fully qualified domain
+name of the host, and **must not** terminate with a dot.
+This requirement seems to be in line with many existing definitions in
+the blockchain; however it deviates from the BIND zone file format, in
+which names that have not terminating dot are automatically expanded
+by attaching the current origin zone to the end of the name.
+
+#### ip attribute
+
+Contains a list of strings representing IPv4 addresses in dotted
+quad notation. For example,
+
+```
+"ip": ["1.2.3.4", "5.6.7.8"]
+```
+
+translates into a series of `A` RRs:
+
+```
+ IN A 1.2.3.4
+ IN A 5.6.7.8
+```
+
+#### ip6 attribute
+
+Contains a list of strings representing IPv6 addresses in semicolon
+quads notation. For example,
+
+```
+"ip6": ["2001:4860:0:1001::68"]
+```
+
+translates into one AAAA RR:
+
+```
+ IN AAAA 2001:4860:0:1001::68
+```
+
+#### tor attribute
+
+Does not translate into any DNS RR. Contains Tor hidden service address.
+
+```
+"tor": "eqt5g4fuenphqinx.onion"
+```
+
+#### i2p attribute
+
+Does not translate into any DNS RR. It is a JSON Map with three
+optional String attributes: `"destination"`, `"name"` and `"b32"`.
+
+```
+"i2p": { "destination": "XaZscx...0jGAAAA"
+ , "name": "example.i2p"
+ , "b32" : "ukeu...nkdq.b32.i2p"
+ }
+```
+
+#### freenet attribute
+
+Does not translate into any DNS RR. Contains Freesite key.
+
+```
+"freenet": "USK@0I8g...xbZ4,AQACAAE/Example/42/"
+```
+
+#### alias attribute
+
+Translates into `CNAME` RR. Invalidates all other attributes.
+
+```
+"alias": "realhost.example.bit"
+```
+
+Notes:
+* Hostname **must** be specified as fully qualified domain
+ name of the host, and **must not** terminate with a dot.
+* Element of the `"map"` with empty key, `"delegate"` and `"import"`
+ are processed before this invalidation takes place.
+
+#### translate attribute
+
+Translates into `DNAME` RR. Invalidates the contents of the `"map"`
+attribute.
+
+```
+"translate": "otherhost.bit"
+```
+
+Notes:
+* Hostname **must** be specified as fully qualified domain
+ name of the host, and **must not** terminate with a dot.
+* Element of the `"map"` with empty key, `"delegate"` and `"import"`
+ are processed before this invalidation takes place.
+
+#### email attribute
+
+Translates into the `email` element of the SOA and RP RRs. The
+value `"email":"user@domain.tld"` becomes `user.domain.tld.`
+in the DNS record.
+
+```
+"email": "hostmaster@example.bit"
+```
+
+#### loc attribute
+
+Translates into `LOC` RR. Value must conform to the format defined
+by [RFC-1876](http://tools.ietf.org/html/rfc1876).
+
+```
+"loc": "46 31 18.000 N 6 34 26.000 E 401.00m 1m 10000m 10m"
+```
+
+#### info attribute
+
+Does not translate into any DNS RR. Contains a JSON object with
+format unspecified at the time of this writing. Intented for
+the registrant information.
+
+#### ns attribute
+
+Translates into `NS` RR. Because it effectively delegates all
+control over the domain to external nameservers, it also invalidates
+all other attributes.
+
+```
+"ns": ["ns.myserver.net", "192.168.3.4"]
+```
+
+Notes:
+* Hostname **must** be specified as fully qualified domain
+ name of the host, and **must not** terminate with a dot.
+* Element of the `"map"` with empty key, `"delegate"` and `"import"`
+ are processed before this invalidation takes place.
+
+#### delegate attribute
+
+Does not translate into any DNS RR. Instead, the value is used as
+a key for namecoin lookup (i.e. the value must be specified with
+the namespace prefix), and the result of the lookup replaces all
+other attributes
+
+```
+"delegate": "s/example74845"
+```
+
+Notes:
+* Element of the `"map"` with empty key, `"delegate"` and
+ `"import"` are processed before this invalidation takes place.
+* Unlike many other attributes, this can only contain a single
+ string as the value, rather than a list.
+
+#### import attribute
+
+Does not translate into any DNS RR. Instead, the value is used as
+the key for namecoin lookup (i.e. the value must be specified with
+the namespace prefix), and the result of the lookup is merged with
+the current domain object.
+
+```
+"import": ["dd/example", "s/example6473"]
+```
+
+#### map attribute
+
+JSON Map object containing subdomain names as its keys and domain
+objects as values. Element of the map with empty key "" has special
+meaning: the value of this map element is merged into the current
+domain object. This operaton happens first when a new domain object
+is analyzed, and is performed recursively. In the result of the
+merge, the `"map"` does not contain the element with empty key.
+Further operatons that can potentially modify the contents of the
+current domain object (`import` and `delegate` lookups) start when
+the empty element of the `"map"` has been recursively merged into
+the current object.
+
+```
+"map": { "www": { "alias" : "www.example.com" }
+ , "www2": { "delegate": "d/example" }
+ }
+```
+
+Note: When a key contains dots ".", it is converted to a nested
+map. Empty elements in the result of split, such as when a dot is
+at the beginning or at the end of the key, or there are
+consequitive dots, are diagnosed as erroneous data.
+
+```
+"map": { "www.uk": { "alias" : "www.example.co.uk" }
+ , "www..us": { "alias" : "www.example.com" }
+ , "smtp.us.": { "alias" : "smtp.example.com" }
+```
+
+is equivalent to
+
+```
+"map": { "uk": { "map": { "www": { "alias" : "www.example.co.uk" }}}
+ , "us": { "map": { "www": { "alias" : "www.example.com" }
+ , "smtp": { "alias" : "smtp.example.com" }}
+ }
+ }
+```
+
+#### fingerprint attribute
+
+Does not translate into any DNS RR. Contains a list of TLS
+certificate fingerprints. Deprecated.
+
+#### tls attribute
+
+Intended to carry attributes as per
+[RFC-6698](http://tools.ietf.org/html/rfc6698) ("DANE").
+
+```
+"tls": {
+ "tcp": {
+ { "443": [ [1, "660008F9...7621B787", 1] ]
+ , "25": [ [1, "660008F9...7621B787", 1] ]
+ }
+ }
+ }
+```
+
+translates into:
+
+```
+_443._tcp TLSA (3 0 1 660008F9...7621B787)
+_25._tcp TLSA (3 0 1 660008F9...7621B787)
+```
+
+The third element of the `TlsObj` heterogenous array is an extention
+to the DANE definition. Value `0` means that this rule is not enforced
+upon subdomains, value `1` means that it is enforced on subdomains.
+Rule defined inside a subdomain `DomObj` that specifies `0` on a rule
+existing in upper domain, that specifies `1` should be ignored. I.e.
+subdomain rule cannot revoke enforcement imposed by an upper domain rule.
+
+#### ds attribute
+
+Translates into `DS` RR. Carries attributes defined by
+[RFC-4034](http://tools.ietf.org/html/rfc4034).
+
+```
+"ds": [ [31381,8,1,"pA1W...ceTI="]
+ , [31381,8,2,"toHB...ndexitQ6j8E="]
+ ]
+```
+
+### Lookup Sequence
+
+Assuming a query is performed for
+`sdN`++"."++{...}++"."++`sd2`++"."++`sd1`++"."++`dom`++".bit"
+(`sdX` list possibly being empty), the lookup process starts by
+querying the database for the object corresponding to `dom`.
+Technically, it is easiest to populate a "seed" DomObj with a
+single attribute `"import"` the value of which corresponds to the
+`dom` name in the Namecoin namespace, which is `"d/" ++ dom`.
+This domain object is then transformed by the following
+recursive sequece: